Daisuke Matsuzaka, coming off the best two-start stretch of his Red Sox career, left Friday night’s game against the Mariners in the fifth inning with right elbow tightness.

Dice-K didn’t show any obvious signs of injury before being removed. Jason Varitek came out to chat with him following an Ichiro Suzuki single in the fifth and then called for the training. After a conversation, he left the game and was replaced by Matt Albers.

Matsuzaka allowed two runs in the first, one of which was uearned. He was changed with a third run, also unearned, after departing in the fifth.

The Red Sox have always opted to tread carefully with Matsuzaka, so it’s safe to assume he’ll be placed on the DL after this one. Rotation depth is an issue for the team at the moment, as the team’s projected six-through-eight starters have all spent time in the bullpen this month. Tim Wakefield is still there, of course. Felix Doubront and Alfredo Aceves both recently returned to Triple-A Pawtucket to start, and Aceves threw five innings in his outing today.

Aceves figures to be the eventual choice to replace Dice-K on the roster, but since he won’t be available for a few days, Michael Bowden could get the callup on Saturday.